Im currently a junior at my highschool, and i am planning on performing an experiment in which i will compare local tap water to locally bottled water and see if there is any scientific justification for paying more for bottled water. I have done some research on the aspect and have found the regulations that the tap water distribuition company has to abide by, these include aspects like hardness, total fecal coliforms, chlorine levels, lead, etc... I would appreciate any guidance in which aspects of the water to test and compare, the most important ones that have a bigger effect on the quality of the water, for example the hardness, chlorine levels, and such. I was also planning on possibly testing 3 locally bottled brands of water and a number of tap water samples from different areas in the city (Maybe 3 or so) for more accuracy. Basically i need advice on how to outline my experiment and possibly which parameters to test, also i considered maybe testing 2 different shipments of the bottled water allong with testing tap water from different locations to improve accuracy and see if the results are consistent. Im planning on discusing this further with an advisor at my local university, but I don´t want to walk in blank on how exactly is the experiment going to be structured. Thanks for all the help, Hope you all had good holidays.